U.S. patent number 10,849,652 [Application Number 15/139,848] was granted by the patent office on 2020-12-01 for devices, systems, and methods for improving access to cardiac and vascular chambers.
This patent grant is currently assigned to Emory University. The grantee listed for this patent is Emory University. Invention is credited to Robert A. Guyton, Saimuralidhar Padala.
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United States Patent |
10,849,652 |
Guyton , et al. |
December 1, 2020 |
Devices, systems, and methods for improving access to cardiac and
vascular chambers
Abstract
Devices, systems and methods are provided for enhancing
mechanical strength of tissue, allowing direct and secure access to
cardiac and vascular structures, either through tiny incisions or
percutaneously. The method for accessing a cardiac chamber or a
vascular conduit may include providing an access channel into
tissue of the chamber or the conduit. The method may also include
providing an energy-transducing element configured to provide heat
within the access channel. The method may further include applying
energy to the tissue or a tissue-stabilizing composition injected
into, around, or adjacent to the tissue to mechanically enhance the
access channel.
Inventors: |
Guyton; Robert A. (Atlanta,
GA), Padala; Saimuralidhar (Atlanta, GA) |
Applicant: |
Name |
City |
State |
Country |
Type |
Emory University |
Atlanta |
GA |
US |
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Assignee: |
Emory University (Atlanta,
GA)
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Family
ID: |
1000005212528 |
Appl.
No.: |
15/139,848 |
Filed: |
April 27, 2016 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20160235439 A1 |
Aug 18, 2016 |
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Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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13825871 |
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PCT/US2011/054932 |
Oct 5, 2011 |
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61389936 |
Oct 5, 2010 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61B
17/0057 (20130101); A61N 7/02 (20130101); A61B
18/1492 (20130101); A61B 17/3423 (20130101); A61B
17/3439 (20130101); A61M 37/00 (20130101); A61B
18/1482 (20130101); A61B 34/70 (20160201); A61M
2210/125 (20130101); A61M 2037/0007 (20130101); A61N
2007/025 (20130101); A61B 2017/3425 (20130101); A61N
7/022 (20130101); A61B 2017/0061 (20130101); A61B
2017/00659 (20130101); A61B 2018/00351 (20130101); A61B
2017/00606 (20130101); A61B 2018/00577 (20130101); A61B
2017/00243 (20130101); A61N 1/0592 (20130101); A61B
18/1815 (20130101); A61B 2018/0016 (20130101); A61B
2018/0063 (20130101) |
Current International
Class: |
A61B
18/14 (20060101); A61N 7/02 (20060101); A61M
37/00 (20060101); A61B 17/00 (20060101); A61B
17/34 (20060101); A61B 34/00 (20160101); A61B
18/00 (20060101); A61N 1/05 (20060101); A61B
18/18 (20060101) |
References Cited
[Referenced By]
U.S. Patent Documents
Other References
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Catheter Ablation of Ventricular Tachycardia" Circulation:
Arrhythmia and Electrophysiology, 2010, 3(2): 178-185. cited by
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Glue-Spread Stapler Prevents Air Leakage from the Lung" The Annals
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Consecutive Patients: Excellent Outcome in Very High-Risk Patients"
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813-820. cited by applicant .
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Wire, 2010, retrieved from from the Internet
<URL:http://http://www.businesswire.com/news/home/20100922006237/en/Re-
Cor-announces-successful-first-in-human-clinical-case-ultrasound#.VZrHy_IV-
hBc> on Jun. 4, 2015. cited by applicant .
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Device & Diagnostic Industry Magazine, 1998, retrieved from the
Internet
<URL:http://www.mddionline.com/article/next-wave-minimally-invasive-su-
rgery> on Jun. 4, 2015. cited by applicant .
Walther et al. "Human Minimally Invasive Off-Pump Valve-in-a-Valve
Implantation" The Annals of Thoracic Surgery, 2008; 85(3):
1072-1073. cited by applicant .
Office Action dated Mar. 11, 2015, by the Examiner in U.S. Appl.
No. 13/825,871. cited by applicant .
Office Action dated Oct. 27, 2015, by the Examiner in U.S. Appl.
No. 13/825,871. cited by applicant.
|
Primary Examiner: Peffley; Michael F
Assistant Examiner: Ouyang; Bo
Attorney, Agent or Firm: Emory Patent Group
Parent Case Text
CROSS REFERENCE TO RELATED APPLICATIONS
This application is a division of U.S. application Ser. No.
13/825,871 filed Mar. 25, 2013, which is a National Stage of
International Application Number PCT/US2011/054932 filed Oct. 5,
2011, which claims priority to U.S. Provisional Application No.
61/389,936 filed Oct. 5, 2010. The entirety of each of these
applications is hereby incorporated by reference for all purposes.
Claims
The invention claimed is:
1. A method for accessing a cardiac chamber or a vascular conduit
of a heart for an interventional procedure, comprising: forming an
access channel into a tissue of an apical area of the heart by
inserting an instrument that includes at least one energy
transducing element; advancing a sheath over the instrument within
the access channel so that the at least one energy-transducing
element of the instrument corresponds to a section of the sheath,
the section being configured to contact and to transmit energy
through the sheath to the tissue surrounding the sheath; and
applying the energy from the instrument through the sheath to heat
the tissue of the access channel surrounding the sheath so that the
tissue of the access channel radially contracts around the sheath
to mechanically enhance the access channel.
2. The method of claim 1, further comprising: delivering a
tissue-stabilizing composition prior to applying the energy,
wherein the energy is applied to the tissue-stabilizing
composition.
3. The method of claim 1, wherein the energy includes microwave,
ultrasound, RF, or heat energy.
4. The method of claim 1, wherein the energy includes ultrasound
energy and the ultrasound energy heats the tissue surrounding the
sheath.
5. The method of claim 1, wherein: the sheath includes a section
configured to transmit the energy delivered by the at least one
energy-transducing element through the sheath to the surrounding
tissue; and the sheath is advanced so that the at least one
energy-transducing element corresponds to the section of the
sheath.
6. The method of claim 5, wherein the section contacts the at least
one energy-transducing element when inserted.
7. The method of claim 1, further comprising: inserting one or more
instruments for the interventional procedure through the sheath
provided in the mechanically enhanced access channel; and removing
a portion of the sheath so that a remaining portion of the sheath
remains in the access channel after the access channel is
sealed.
8. A method for accessing a cardiac chamber or a vascular conduit
of a heart for an interventional procedure, comprising: providing
an access channel into a tissue of the apical area of the heart;
providing a heart access device within the access channel, the
heart access device including at least one energy-transducing
element being configured to deliver energy to tissue of the access
channel surrounding the sheath; applying the energy from the at
least one energy-transducing element to heat the tissue of the
access channel surrounding the heart access device so that the
tissue of the access channel radially contracts around the heart
access device to mechanically enhance the access channel; inserting
one or more instruments for the interventional procedure through
the heart access device provided in the mechanically enhanced
access channel; and removing a portion of the heart access device
so that a remaining portion of the heart access device remains in
the access channel after the access channel is sealed.
9. The method of claim 8, further comprising: delivering a
tissue-stabilizing composition prior to applying the energy,
wherein the energy is applied to the tissue-stabilizing
composition.
10. The method of claim 8, wherein the energy includes microwave,
ultrasound, RF, or heat energy.
11. The method of claim 8, wherein the energy includes ultrasound
energy and the ultrasound energy heats the tissue surrounding the
sheath.
12. The method of claim 8, further comprising: inserting a sealing
device into the heart access device; wherein the portion of the
heart access device is removed after insertion of the sealing
device.
13. The method of claim 8, wherein the heart access device includes
a sheath and an introducer, the introducer including the
energy-transducing element, the method further comprising: forming
an access channel into the tissue of an apical area of the heart by
inserting the introducer that includes the energy-transducing
element.
14. A method for accessing a cardiac chamber or a vascular conduit
of a heart for an interventional procedure, comprising: forming an
access channel into a tissue of the chamber or the conduit by
inserting an introducer that includes an energy-transducing element
configured to deliver the energy; advancing a sheath over the
introducer so that the energy-transducing element of the introducer
corresponds to a section of the sheath, the section being
configured to contact and to transmit energy through the sheath to
the tissue surrounding the sheath; and applying the energy from the
introducer through the sheath at the section to heat the tissue of
the access channel surrounding the sheath so that the tissue of the
access channel radially contracts around the sheath to mechanically
enhance the access channel.
15. The method of claim 14, further comprising: delivering a
tissue-stabilizing composition prior to applying the energy,
wherein the energy is applied to the tissue-stabilizing
composition.
16. The method of claim 14, wherein the access channel is in an
apical area of the heart.
17. The method of claim 14, wherein: the energy includes microwave,
ultrasound, RF, or heat energy.
18. The method of claim 14, wherein the energy includes ultrasound
energy and the ultrasound energy heats the tissue surrounding the
sheath.
19. The method of claim 14, further comprising: inserting one or
more instruments for the interventional procedure through the
sheath provided in the mechanically enhanced access channel; and
removing a portion of the sheath so that a remaining portion of the
sheath remains in the access channel after the access channel is
sealed.
Description
FIELD
The present disclosure provides devices and methods for improved
cardiac and vascular access to allow minimally invasive replacement
or repair of cardiac and vascular structures. Such devices and
methods rely on increasing the strength of the heart tissue or
vascular wall to allow safer manipulation and reduced potential for
catastrophic side effects.
BACKGROUND
Various types of surgical procedures are currently performed to
investigate, diagnose, and treat certain cardiovascular disorders.
Such procedures include repair and replacement of mitral, aortic,
and other heart valves, repair of atrial and ventricular septal
defects, pulmonary thrombectomy, treatment of aneurysms,
electrophysiological mapping and ablation of the myocardium, and
other procedures in which interventional devices are introduced
into the interior of the heart or a vascular structure.
Using current techniques, many of these procedures require a gross
thoracotomy to gain access into the patient's thoracic cavity and
cardiac or vascular structures. A relatively large opening into the
thoracic cavity is created through which the surgical team may
directly visualize and operate upon the heart and other thoracic
contents. Open-chest valve replacement surgery has the benefit of
permitting the direct implantation of the replacement valve at its
intended site. This method, however, is highly invasive and often
results in significant trauma, risk of complications, as well as an
extended hospitalization and a painful recovery period for the
patient.
Minimally invasive valve replacement procedures have emerged as an
alternative to open-chest surgery. Two types of minimally invasive
valve procedures that have emerged are percutaneous valve
procedures and trans-apical valve procedures. Percutaneous valve
procedures pertain to making small incisions in the skin to allow
direct access to peripheral vessels or body channels to insert
catheters. Trans-apical valve procedures pertain to making a small
incision in or near the apex of a heart to allow valve access.
Because minimally invasive approaches require smaller incisions,
they generally allow for faster patient recovery with less pain and
bodily trauma. This, in turn, reduces the medical costs and the
overall disruption to the life of the patient.
Minimally invasive trans-apical valve replacement procedures have
emerged as an alternative to both open chest surgery and
percutaneous valve surgeries. The use of minimally invasive
approaches, however, highlights certain complexities in the
surgery. Unlike open heart surgery, minimally invasive heart
surgery offers a small surgical field that greatly reduces the
surgeon's field of view and, consequently, the ability of the
surgeon to detect complications as they arise. U.S. Patent
Publication No. 2005/0240200 to Bergheim et al. presents certain
methods and systems for the repair, removal, and/or replacement of
heart valves through the apex of the heart. Similarly, U.S. Patent
Publication No. 2007/0112422 to Dehdashtian provides a delivery
system and method for delivering heart valves via a device that
passes through the apex of the left ventricle.
Although there are a number of methods and devices available to
assist in these procedures, the incidence of complications remains
high, particularly in high risk and elderly populations. See for
example, Hsieh, et al. 2010 Circulation: Arrhyth. Electrophys.
3:178-185, Pasic, et al. (2010) J. Am. Coll. Cardiol. 56:813-20 and
Walther et al (2008) Ann Thorac Surg. 85(3): 1072-1073.
SUMMARY
There remains a need for improved methods and devices that allow
the surgical manipulation through trans-apical or trans-cardiac
wall access while reducing the likelihood that a patient's heart
muscle will weaken or tear and release the access device. If such
methods and devices can provide security from bleeding and tissue
disruption during and after the period of access to the cardiac
chambers or vascular structure, then such access may not require
even a minimally invasive incision or thoracotomy, but may be
performed percutaneously, potentially under local anesthesia.
In some embodiments, the disclosure relates to the use of certain
devices, compositions and methods for enhancing the strength of
tissue at a cardiac and/or vascular chamber access site (also
referred to access channel). In some embodiments, the disclosure
provides methods, systems and devices that are configured or
structured to stabilize the access channel by mechanically
enhancing or strengthening the access channel. In some embodiments,
the methods, systems, and devices relate to delivering energy to
stabilize the access channel. In other embodiments, the methods,
systems, and devices relate to delivering a tissue-stabilizing
composition to stabilize the access channel in addition to or in
alternative of delivering energy to stabilize the access
channel.
In some embodiments, the disclosure relates to heart access devices
and systems. The heart access devices and systems may be configured
or structured to provide a mechanically enhanced access channel
within tissue or muscle of the heart. According to some
embodiments, the heart access device may include a sheath including
an open channel configured or structured to accept an
interventional device, the sheath being configured to be inserted
into the access channel. The heart access device may further
include at least one energy-transducing component configured to
deliver energy to tissue surrounding the sheath, the
energy-transducing component being configured to cause the
surrounding tissue to stabilize around the sheath. The heart access
device may include a plurality of energy-transducing components,
the plurality of energy-transducing components being disposed in a
pattern. In some embodiments, the energy-transducing component may
be configured to heat a tissue-stabilizing composition.
In some embodiments, the heart access device may include a sleeve.
The sleeve may include the at least one energy-transducing
component. The sleeve may be configured to surround the sheath. The
sleeve may be configured to be movable with respect to the
sheath.
In other embodiments, the device may include an introducer
configured to form the access channel. In some embodiments, the
sleeve may be configured to surround the introducer.
In some embodiments, the device may include a sheath including an
open channel configured to accept an interventional device; and an
introducer including at least one least one energy-transducing
element configured to delivery energy. The open channel of the
sheath may be configured to accept the introducer, the introducer
being movably disposed with respect to the sheath. The open channel
may also be configured to accept another device configured to
manipulate a valve or inner cardiac chamber of the heart. The
introducer may include an inner channel configured to accept a
guidewire.
In some embodiments, the introducer may include a section that has
a cross section that is equal or slightly less than a diameter of
the inner channel of the sheath. The introducer may include a
puncture tip. In some embodiments, the introducer may include a
guide member having a cross section that is larger than an inner
diameter of the inner channel.
In some embodiments, the device may further include a power source,
the power source configured to deliver power to the at least one
energy-transducing element. In some embodiments, the sheath may
include at least one energy focusing or dispersing element, the at
least one energy focusing element being configured to focus the
energy on at least one of surrounding tissue or a
tissue-stabilizing composition surrounding a portion of the heart
access device. The at least one energy focusing component may
correspond to or compliment the energy-transducing component. In
some embodiments, the energy-transducing component may be
configured to deliver microwave, ultrasound, radiofrequency (RF),
or heat energy.
In some embodiments, the device may further include a sealing
device configured to seal the access channel. The sealing device
may be a plug. In some embodiments, the sealing device may be of a
wound bioabsorbable material and/or a pre-formed hydrophilic
material. In further embodiments, the sealing device may further
include a base. The base may include an open channel configured to
be disposed on a sealing device delivery device, such as an
introducer. In some embodiments, the sealing device may further
include extending members that extend from an elongated section
constructed or made of a wound bioabsorbable material and/or a
pre-formed hydrophilic material. The extending members may be
constructed or made of a bioabsorable material. In some
embodiments, the sealing device may further include a clip member.
The clip member may be constructed or made of a memory shape
alloy.
In some embodiments, the device may further include a sealing
device introducer, the sealing device introducer configured to be
anchor the sealing device within the access channel. The sealing
device introducer may include external threads and the sheath may
include internal threads, the threads of the sealing device
introducer and the threads of the sheath being complementary. The
sealing device introducer may further include a release mechanism
configured to release the sealing device within the access
channel.
In some embodiments, the sealing device may further include at
least one sensor. The sensor may be configured to monitor cardiac
conduction currents in myocardium. The sealing device may be
configured to be anchored to the surrounding tissues by a fastener.
The fastener may include one or more needles mounted in a
pattern.
In some embodiments, the device may further include an energy
source, the energy source configured to deliver energy through the
heart access device. The heart access device may be configured to
focus the energy on at least one of surrounding tissue or a
tissue-stabilizing composition surrounding a portion of the heart
access device.
In some embodiments, the disclosure provides a heart access device
that may include a sheath including an open channel configured to
accept an interventional device; and a delivery device configured
to deliver a tissue-stabilizing composition into, around, or
adjacent to the tissue surrounding the sheath, the
tissue-stabilizing composition configured to mechanically enhance
the tissue surrounding the sheath. In further embodiments, the
heart access device may include an energy-transducing element
configured to deliver energy to at least one of the tissue
surrounding the sheath and the tissue-stabilizing composition, the
energy-transducing component being configured to cause the
surrounding tissue to stabilize around the sheath.
In some embodiments, the disclosure provides a device configured to
provide access to the chambers of a beating heart or a vascular
conduit. The device may include a sheath including an open channel
configured to be inserted into a muscle of the heart or a wall of
the vascular conduit to access an inner chamber of the heart or a
vascular lumen of the vascular conduit, and configured to accept an
interventional device. The device may include an introducer
including atleast one energy-transducing element configured to
deliver energy to the tissue surrounding the sheath for
stabilization and strengthening. The device may also include
sealing device configured to be delivered into the access
channel.
The sealing device may be configured to close the access channel
permanently or reversibly so that the access channel may be
accessed at a later time.
In some embodiments, the sheath may include a section constructed
of a material that conducts energy than remainder of the sheath.
The sheath may include a section that has a different thickness
than the remainder of the sheath. The sheath may include a section
that is configured to focus energy to a specific location in the
tissue surrounding the sheath.
The device may further include a sleeve. The sleeve may include at
least one energy-dispersing element or energy-transducing element.
The sleeve may be structured to surround the sheath. The sleeve may
be movable with respect to the sheath. The device may further
include an sealing device configured to be inserted into the open
channel of the sheath, the introducer being disposed with respect
to the sheath. The introducer may include a section having at least
one or more energy-dispersing elements or energy-transducing
elements. The energy-dispersing elements or energy-transducing
elements being disposed in a pattern. The introducer may include an
access channel.
The sleeve may include at least one energy-dispersing element or
energy-transducing element configured to surround the introducer.
The energy-transducing element may be configured to deliver a
plurality of forms of energy, the forms may include heat,
radio-frequency, ultra-sound or microwave. The sealing device may
include a first section that is configured to close or seal the
access channel and a second section configured to enable releasably
attachment to a delivery introducer. The sealing device may be
constructed of one of or any combination of a biological material,
a biocompatible polymer, or a metal.
The device may further include a sealing device introducer
configured to deliver the sealing device through the sheath into
the access channel. The sealing device introducer may include
threads on an outside surface and the sheath may include the
threads within the channel. The threads of the sealing device
introducer and the threads of the sheath may be complementary.
In certain embodiments, the disclosure provides a heart access
device that allows insertion through a heart wall and includes an
energy-transducing element on at least one portion of an insertion
sleeve. In certain embodiments, the heart access device may include
a sheath with an open channel configured to accept an
interventional device. In further embodiments, the device may
include a sleeve that is attached to or makes up at least a part of
the sheath, wherein the sleeve is configured to provide energy to a
surrounding tissue. In certain embodiments, the sleeve may be
configured to heat the surrounding tissue. In other embodiments,
the energy-transducing element (device) may be introduced
separately from the sleeve during the procedure. In some
embodiments, the heart access device may include a sheath with an
open channel configured to accept an interventional device, and a
sleeve that is attached to or makes up at least a part of the
sheath, wherein the sleeve is configured to provide a tissue
strengthening composition to surrounding tissue. Typically, the
sleeve may be a sheath, tube or cannula. The sleeve is typically
configured so as to provide a rigid channel through the wall of the
heart. Typically, the sleeve may include an energy-transducing
element on its tip. In certain embodiments, the element may be a
heating element. In some embodiments, the element may surround the
sleeve. The element may include coils that surround the sleeve. The
element may be typically configured to surround the sleeve for at
least 3 mm, or at least 6 mm, or at least 9 mm, or at least 12 mm,
or at least 15 mm. Typically, the element may surround the sleeve
for a distance sufficient to contact a portion of the tissue at the
wall of a heart, but does not expand beyond the wall of the
heart.
The energy-transducing element may be a mechanism for providing
high frequency energy, which can include radiofrequency, ultrasound
or microwave energy. In some embodiments, the sleeve may include a
tissue contacting member that includes an array of electrodes which
can penetrate the tissue surrounding the sleeve. Typically, the
electrodes may include a radiofrequency electrode, a focused
ultrasound electrode (i.e. transducer) or a combination of these.
In some embodiments, the sleeve may include a tissue contacting
coil for generating heat. The term "heating element" as used herein
encompasses elements that apply energy thereby inducing heat in the
tissue as well as to elements that apply heat to the tissue. In a
preferred embodiment, the tissue may be heated to a temperature in
the range of about 40 degrees Celsius to about 110 degrees Celsius,
more preferably about 60 degrees Celsius to about 65 degrees
Celsius.
In some embodiments, the disclosure provides a method of accessing
a cardiac chamber including: (i) providing an access channel into
the chamber; (ii) providing an energy-transducing element
configured to provide heat or to cool tissue surrounding the access
channel; and (iii) applying energy to the tissue. In certain
embodiments, the method may further include modifying the tissue
with a strength-enhancing compound (may also be referred to as a
"tissue-stabilizing composition" or "tissue-stabilizing compound")
prior to applying the energy. In some embodiments, the
energy-transducing element may heat the tissue.
In some embodiments, the disclosure provides a method for accessing
a cardiac chamber or a vascular conduit. The method may include:
providing an access channel into tissue of the chamber or the
conduit; providing an energy-transducing element configured to
provide heat within the access channel; and applying energy to the
tissue or a tissue-stabilizing composition injected into the tissue
to mechanically enhance the access channel. The energy may be
applied to the tissue, and the energy heats the tissue. In some
embodiments, the method may further include delivering the
tissue-stabilizing composition prior to applying the energy. The
energy may additionally or alternatively be applied to the
tissue-stabilizing composition.
In other embodiments, the disclosure provides a method of accessing
a cardiac chamber including: (i) providing an access channel into
the chamber; (ii) modifying the tissue surrounding the access
channel with a strength-enhancing compound; and (iii) closing the
access channel.
In some embodiments, the method may further include delivering a
tissue-stabilizing composition prior to applying the energy. The
energy may be applied to the tissue-stabilizing composition. In
further embodiments, the method may further include positioning or
inserting a sealing device into the access channel.
BRIEF DESCRIPTION OF THE FIGURES
The disclosure can be better understood with the reference to the
following drawings and description. The components in the figures
are not necessarily to scale, emphasis being placed upon
illustrating the principles of the disclosure.
FIG. 1 is a diagram of the heart, showing an access port or channel
through the apex.
FIGS. 2A-2D are diagrams detailing the Seldinger method for
providing tissue access according to embodiments. FIG. 2A shows a
guidewire being inserted through a trocar into the tissue. FIG. 2B
shows retraction of the needle. FIG. 2C shows the rotational
insertion of a catheter over the guidewire to increase the diameter
of the access port. FIG. 2D shows insertion of the sheath into the
access port.
FIG. 3 shows the initial insertion of the sheath of the
disclosure.
FIG. 4 is a diagram of a heart access device according to
embodiments.
FIG. 5 shows the insertion of a heart access device into the tissue
of the heart according to embodiments.
FIG. 6 shows a detail of injection of a tissue-stabilizing
composition into the tissue surrounding the access port (also
referred to as "access channel").
FIG. 7 shows a different embodiment detail of injection of a
tissue-stabilizing composition into the tissue surrounding the
access port.
FIG. 8 shows inflation of a balloon to retract the sleeve into the
appropriate position.
FIG. 9 shows insertion of a sealing to close the access port, and
removal of the remainder of the sheath from the sleeve.
FIGS. 10 and 11 show a heart access device including a fastener
according to embodiments.
FIG. 12 shows an introducer according to embodiments.
FIG. 13 shows a sheath according to embodiments.
FIG. 14 shows a heart access device according to embodiments.
FIGS. 15A-15C show a heart access device according to different
embodiments.
FIGS. 16A-16D show sealing devices according to embodiments.
FIG. 17 shows a sheath according to embodiments.
FIG. 18 shows a sealing device introducer according to
embodiments.
FIG. 19 shows a detail of identifying the location for performing a
method according to embodiments.
FIG. 20 shows a detail of inserting an access device according to
embodiments.
FIG. 21 shows a detail of positioning the access device according
to embodiments.
FIG. 22 shows a detail of applying energy to surrounding tissue
according to embodiments.
FIG. 23 shows a detail of positioning the sheath to perform medical
procedures according to embodiments.
FIG. 24 shows a detail of introducing a sealing device introducer
according to embodiments.
FIG. 25 shows a detail of positioning the sealing device according
to embodiments.
FIG. 26 shows a detail of retracting the access device according to
embodiments.
FIG. 27 shows the removal of the access device according to
embodiments.
FIG. 28 shows an example of a heart access device according to
embodiments.
FIGS. 29 through 34 show details of the method according to
embodiments performed on a pig heart.
FIGS. 35 through 39 show results of the method shown in FIGS. 29
through 34.
DETAILED DESCRIPTION
The present disclosure provides methods, devices, and systems for
providing access to the heart or heart vessels to perform
cardiovascular surgery. The access may be provided by forming an
access channel through the heart tissue or muscle (the
myocardium).
The methods may include the step of, and devices, and systems may
be configured or configured to provide stable access to the heart
tissue or muscle. The methods, devices, and systems are configured
or structured to stabilize the heart muscle or tissue surrounding
the access channel so as to prevent the release of an access
device. The methods, devices, and systems include a heart access
device that includes a sheath. The methods, devices, and systems
are configured or structured to stabilize the heart muscle or
tissue surrounding the sheath so as to prevent the release of an
access device. The methods, devices, and systems are configured or
structured to mechanically enhance (strengthen) the tissue of the
access channel.
In some embodiments, the methods may include the step, devices and
systems may be configured or structured to deliver heat or energy
passively to the heart tissue through the sheath causing the heart
tissue to shrink tightly around the sheath and seal the tissue
around the sheath. This results in stable access to the channel
inside the sheath to perform interventional and diagnostic
procedures. The energy may be applied by transducers provided on a
wall of the sheath (directly or indirectly by a sleeve) or by a
heating element or energy source (e.g., high-energy focused
ultrasound) built into an introducer.
In other embodiments, the methods may include the steps of, and
devices, and systems may be configured to deliver a
tissue-stabilizing composition. in addition to or in alternative to
delivering energy, to the surrounding tissue. The
tissue-stabilizing composition may further mechanically enhance or
stabilize the access channel.
According to embodiments, because the tissue surrounding the sheath
has been stabilized (mechanically enhanced), it is possible to seal
the access channel with a sealing device.
General Method to Access the Heart
Transapical cardiac surgery is not a new procedure. Levy and
Lillehei described a technique for percutaneous direct cardiac
catheterization in 1964 (Levy and Lillehei (1964) NEJM271:273-280).
The technique has been used since then, however percutaneous venous
access is typically preferred. U.S. Patent Publication No.
2007/0112422 describes a general method and device for transapical
heart valve delivery system. The method generally includes
inserting an instrument through the subject's chest wall and
through the heart wall. The instrument carries on its distal end a
movable element which is manipulated to grasp a valve leaflet and
hold it while a needle mechanism punctures the valve leaflet and
loops a suture around a portion of the valve leaflet.
A general method of introducing a stent or sleeve into a heart apex
is diagrammed in FIG. 1. The access system 30 is shown penetrating
through the apex 12 of the heart 10. The moving direction of the
access system is indicated by the arrow. The access system may
enter either the right ventricle 17 or the left ventricle 15. To
access the aortic or mitral valve, the access system typically
passes through the left ventricle. This yields direct access to the
aortic or mitral valve. To access the pulmonary or tricuspid valve,
the access system would typically pass through the right
ventricle.
The access system is diagrammed in FIG. 2. Typically, the technique
used is the Seldinger technique for progressive dilation of the
access channel. The access channel may be formed in a blood vessel
as shown in FIG. 2 or in a cavity, such as a heart chamber as shown
in FIG. 1. An access system 25 (here shown as a typically sharp
hollow needle called a trocar) may be used to puncture the desired
vessel or cavity, with ultrasound guidance if necessary to form an
access channel. A round-tipped guidewire 22 may then advance
through the lumen of the trocar, and the trocar is withdrawn. A
blunt cannula or introducer 29 may then be passed over the
guidewire into the cavity or vessel to increase the size of the
opening. In the alternative, an introducer having a puncture tip at
the end may be used to puncture the desired vessel or cavity. After
the opening is of the appropriate size, a tube or sheath 40 may be
introduced, in this instance including a sleeve as described herein
and the guidewire may be withdrawn.
The tube or sheath 40 may be used to introduce catheters or other
devices to perform endoluminal (inside the hollow organ)
procedures, such as angioplasty. Fluoroscopy may be used to confirm
the position of the catheter and to maneuver it to the desired
location. Injection of radiocontrast may be used to visualize
organs. Interventional procedures, such as thermoablation,
angioplasty, embolization or biopsy, may be performed. Upon
completion of the desired procedure, the access port may be closed
as described herein and the tube or sheath may be withdrawn. In
certain embodiments, a sealing device may be used to close the hole
made by the procedure.
In addition to grasping and needle mechanisms, instruments used for
repair procedures often include fiber optics that provide direct
visual indication that the valve leaflet is properly grasped. A set
of illuminating fibers terminate at the distal end of the
instrument around the needle mechanism in close proximity to a set
of sensor fibers. The sensor fibers may convey light from the
distal end of the instrument to produce an image for the operator.
When a valve leaflet is properly grasped, light from the
illuminating fibers may be reflected off the leaflet surface back
through the sensor fibers. On the other hand, if the valve leaflet
is not properly grasped, the sensor fibers may sense or view
blood.
The present disclosure provides methods, devices and systems for
performing cardiovascular surgery, wherein access to the heart or
great vessels may be provided through the heart muscle. In
preferred embodiments, access may be provided through the apical
area of the heart. The apical area of the heart is generally the
blunt rounded inferior extremity of the heart formed by the left
and right ventricles. In normal healthy humans, it generally lies
behind the fourth or fifth left intercostal space in the
mid-clavicular line.
The unique anatomical structure of the apical area permits the
introduction of various surgical devices and tools into the heart
without significant disruption of the natural mechanical and
electrical heart function. While access to the heart through
peripheral (e.g. femoral, jugular, etc.) vessels in percutaneous
methods are limited to the diameter of the vessel (approximately 1
to 8 mm), access to the heart through the apical area may be
significantly larger (approximately 1 to 25 mm or more). Moreover,
apical access is dramatically closer to intracardiac structures
than access through peripheral vessels. Thus, apical access to the
heart permits greater flexibility with respect to the types of
devices and surgical methods that may be performed in the heart and
great vessels.
It should be noted that while reference is made herein of
trans-apical procedures, it is intended for such procedures to
encompass access to the heart through any wall thereof, and not to
be limited to access through the apex only. While the apical area
is particularly well suited for the purposes of the present
disclosure, for certain applications, it may be desirable to access
the heart at different locations, all of which are within the scope
of the present disclosure.
Devices and Systems
According to embodiments, the access devices and systems may be
configured or structured to strengthen a patient's heart muscle so
as to reduce the likelihood that the patient's heart muscle will
weaken and release an access device.
In some embodiments, the access device may include at least one
sheath. In some embodiments, the access device may include one
sheath. In other embodiments, the access device may include one
sheath that has more than one section. In certain embodiments, the
access device may include more than one sheath. Each sheath may
have one or more than one section.
Referring to FIGS. 3 and 4, in some embodiments, the access device
400 may include the sheath 40. The sheath 40 may be of any shape.
The sheath 40 may be in the form of an elongated tube. The sheath
40 may include an interior bore or channel 42 extending between its
proximal and distal ends.
In certain embodiments, the sheath 40 may include more than one
section. In some embodiments, the sheath 40 may include a first
section that is relatively stiff and a second section that is
relatively flexible. In certain embodiments, the sheath 40 may
include a relatively stiff wall section extending from its distal
end 41 to juncture 43 (also referred to as "distal section"), and a
relatively limber wall section throughout the rest of the sheath
(also referred to as "proximal section"). Alternatively, the sheath
may have stiffness throughout its entirety.
The sheath 40 may be arranged so that at least one section is
"torquable." That is, at least the proximal section of the sheath
may be arranged to transmit torsional motion about its axis. Thus,
by turning the proximal end of the sheath, the distal end of the
sheath may also be rotated about an axis.
In some embodiments, the access device 400 may be configured to
receive or accept and introduce medical instruments for procedures
to be performed such interventional and diagnostic procedures to a
chamber of the heart. The inner channel 42 of the sheath 40 may be
configured to receive or accept medical instruments. In other
embodiments, an end of the access device 400 may be configured to
connect to an interventional and/or diagnostic device. The access
device 400 may be configured to connect to a connecting device.
In some embodiments, the access device may be configured to
introduce catheters or other devices to perform endoluminal (inside
the hollow organ) procedures, such as angioplasty. Fluoroscopy may
be used to confirm the position of the catheter and to maneuver it
to the desired location. Injection of radiocontrast may be used to
visualize organs. Interventional procedures, such as
thermoablation, angioplasty, embolization, biopsy, or deployment of
stents or replacement or repair valve devices may be performed.
The device 400 may be configured to receive or accept imaging
devices. The system may also further include imaging devices. In
addition to grasping and needle mechanisms, instruments used for
repair procedures often include fiber optics that provide direct
visual indication that the valve leaflet is properly grasped. A set
of illuminating fibers terminate at the distal end of the
instrument around the needle mechanism in close proximity to a set
of sensor fibers. The sensor fibers convey light from the distal
end of the instrument to produce an image for the operator. When a
valve leaflet is properly grasped, light from the illuminating
fibers is reflected off the leaflet surface back through the sensor
fibers. On the other hand, if the valve leaflet is not properly
grasped, the sensor fibers see blood.
The heart access device 400 may further include a manipulating
instrument 44 that is slidably mounted thereon and that may be
configured to be manipulated. The manipulating instrument 44 may be
slidably mounted onto the sheath. The manipulating instrument 44
may be a guidewire.
An expandable balloon may be advanced over the guide wire into the
cardiac chamber, illustratively in the form of balloon 80. When
inflated, as depicted in FIG. 8, the balloon may generally be in
the form of a surface of revolution about a central axis coincident
with proximal-to-distal axis of the catheter. The diameter of the
balloon may typically be about 20 mm and may usually be formed from
a polymer such as nylon with a wall thickness of about 8 microns to
about 30 microns. When deflated, the balloon may collapse inwardly
to form a relatively small diameter structure. The balloon may be
fabricated by blow-molding using techniques that are known in the
art. Typically, the balloon may be advanced after insertion of the
sheath and expanded within the ventricle. After inflation, the
balloon may then be pulled on to move the sleeve 45 so that the
distal end of the sleeve is coincident with the interior of the
tissue. This positioning of the sheath may be accomplished either
before or after the tissue strengthening procedure.
In some embodiments, the access device may include at least one
energy-transducing component or element. The energy-transducing
component (also referred to as "energy-transducing element) may be
configured to heat and thus denature collagen fibers and other
proteins within the surrounding tissue. The energy-transducing
element may be a mechanism for providing high frequency energy,
which may include radiofrequency, ultrasound or microwave energy.
The energy-transducing element may be a heating element configured
to heat and thus denature collagen fibers within the surrounding
tissue. In some embodiments, the energy-transducing element may be
configured to deliver energy to the surrounding tissue as described
herein. In further embodiments, the energy-transducing element may
be configured to convert radio-frequency into heat. The
energy-transducing component may be configured to transmit energy
when connected to a power source.
In some embodiments, the access device 400 may include a sleeve 45.
The sleeve 45 may include may have an interior bore or channel 47
extending between its proximal and distal ends.
In some embodiments, the sheath 40 may include the sleeve 45 that
has an energy-transducing component 48, as shown in FIG. 4. In some
embodiments, the sleeve 45 may be provided on all or a portion of
the sheath 40. In other embodiments, the sleeve 45 may be attached
to or extended from the sheath 40.
FIGS. 15(A)-(C) show another example of an access device including
a sheath. In some embodiments, the energy-transducing component(s)
may be disposed on a sleeve configured to be movably disposed
around a sheath, as shown in for example, FIG. 15.
FIGS. 15(A)-(C) show an access device 1500 having a sheath 1510
with a sleeve 1520. The sleeve 1520 may include a plurality of
energy-transducing components 1522. As shown in FIGS. 15(A) and
15(B) show how the sleeve 1520 may be configured to be movable with
respect to the sheath 1510. FIG. 15(C) shows an example of the
access device 1500 being positioned within an access channel in the
myocardium 1530.
In other embodiments, the energy-transducing component(s) may be
integrated with the sheath.
In some embodiments, the sleeve 45 may include one
energy-transducing component. In other embodiments, the sleeve may
include more than energy-transducing components. The sleeve may be
typically made out of a thromboresistant, biocompatible material
such as pyrolytic carbon. Pyrolytic carbon is a turbostratic
carbon, which are materials that are structurally similar to
graphite but have greater durability. The sleeve may also be made
out of some material that can withstand heat.
In some embodiments, the energy-transducing component may include
an ultrasonic transducer. In some embodiments, the heart access
device may include a tubular, cylindrical ultrasonic transducer.
The sleeve typically may include a tubular, cylindrical ultrasonic
transducer. The transducer may be mounted on the sleeve. Such a
transducer may be coaxial or nearly coaxial with the sleeve, and
arranged so that the transducer extends axially over at least part
of the sleeve. Merely by way of example, the transducer may have an
axial length of about 6 mm and an outside diameter of about 2-3 mm.
Typically, the proximal end of the transducer will not extend out
of the tissue when the sleeve is anchored or placed within the
heart. In some embodiments, the transducer may be formed from a
ceramic piezoelectric material. The tubular transducer may have
metallic coatings on its interior and exterior surfaces.
In some embodiments, the sheath 40 may include RF electrode wires
inside the sleeve 45, and the electrodes are surrounded by an
insulating sleeve axially moveable thereon; the sleeve is retracted
to expose a predetermined portion of the electrode; and RF energy
is applied to the tissue through the electrode to cause heating of
the tissue. In other embodiments, an RF electrode wire is
positioned on the sleeve 45 and is exposed to tissue upon insertion
of the sleeve.
In some embodiments, the heart access devices and systems may
further include a wiring support tube 49. The wiring support tube
49 may be provided within along all or a portion of the inner
channel of the sheath. In further embodiments, the wiring support
tube 49 may be provided within along all or a portion of the inner
channel of the sleeve. In some embodiments, the wiring support tube
may be connected to one of the sheath and/or the sleeve. The wiring
support tube 49 may be provided at an end of the heart access
device.
The heart access devices and systems may further include a catheter
that is configured to deliver the wires to the transducer. The
wires may be configured to extend through wiring support tube 49 to
the distal end of the catheter. These wires may extend through the
catheter to the proximal end of the catheter, and may be configured
to be connected to an ultrasonic excitation or power source.
Metallic support tubes and transducers may be typically configured
so that the interior surface of the tubular transducer is spaced
apart from the exterior surface of the tube by a gap distance which
corresponds to approximately one-half the wavelength of the
ultrasonic energy to be applied, i.e., about 83 microns for 9 MHz
ultrasonic energy propagating in water. This promotes efficient
operation of the transducer, with ultrasonic energy reflected at
the exterior surface of support tube reinforcing ultrasonic energy
propagating within the transducer, so as to provide ultrasonic
energy directed outwardly from external surface of the
transducer.
With the sleeve in place and in contact with the tissue, the
energy-transducing element or component 48 may be configured to be
activated. The energy-transducing element 48 may be activated by an
energy or power source. In some embodiments, the energy-transducing
element 48 may be configured to provide energy to surrounding
tissue when the energy source is provided within an inner channel
of sheath. In further embodiments, the energy source may be
additionally or alternative provided within an inner channel of the
sleeve 45.
In some embodiments, the energy source may be configured for
ultrasound energy. In one embodiment, an ultrasonic excitation
source may actuate the transducer to emit ultrasonic waves. In
another embodiment, electrodes may be inserted into the tissue from
the sleeve and either radiofrequency or microwaves are transferred
through the system. Merely by way of example, ultrasonic waves may
have a frequency of about 1 MHz to a few tens of MHz, most
typically about 9 MHz. The transducer typically may be driven to
emit, for example, about 10 watts to about 100 watts of acoustic
power, most typically about 30 to about 40 watts. The actuation may
be continued for about 20 seconds to about a minute or more, most
typically about 40 seconds to about 90 seconds. Optionally, the
actuation may be repeated several times as, for example, about 5
times. The frequencies, power levels, and actuation times may be
varied from those given above. The ultrasonic waves generated by
the transducer propagate generally radially outwardly from the
transducer, outwardly through surrounding tissue. The ultrasonic
waves impinge on the tissues of the heart surrounding the sleeve.
The energy applied by the transducer is effective to heat and thus
denature collagen fibers within the surrounding tissue. It is
expected that, because the energy is dissipated and converted to
heat principally inside the surrounding tissue, the procedure does
not damage the surface of the heart that is in contact with the
blood, and hence does not provoke thrombus formation.
When necessary, it is envisioned that the sheath may include a
cooled liquid circulation system, such as a balloon, that will
reduce the heat provided to the tissue through the sleeve.
Circulation of the cooled liquid during the procedure helps to cool
the transducer and essentially prevents direct heat transfer
between the transducer and the epithelial lying at the surface of
the tissue. However, it is typically expected that the regions of
the epithelium that are not in contact with the sleeve are cooled
by blood flowing over them during the procedure with continued
operation of the heart.
In some embodiments, the heart access devices and systems may
further include a wiring support tube 49. The wiring support tube
49 may be provided within along all or a portion of the inner
channel of the sheath. In further embodiments, the wiring support
tube 49 may be provided within along all or a portion of the inner
channel of the sleeve. In some embodiments, the wiring support tube
may be connected to one of the sheath and/or the sleeve. The wiring
support tube 49 may be provided at an end of the heart access
device.
In some embodiments, the heart access devices and systems may
further include a catheter that is configured to deliver the wires
to the transducer. The wires may be configured to extend through
wiring support tube 49 to the distal end of the catheter. These
wires may extend through the catheter to the proximal end of the
catheter, and are configured to be connected to an ultrasonic
excitation source. Metallic support tubes and transducers may be
typically configured so that the interior surface of the tubular
transducer is spaced apart from the exterior surface of the tube by
a gap distance which corresponds to approximately one-half the
wavelength of the ultrasonic energy to be applied, i.e., about 83
microns for 9 MHz ultrasonic energy propagating in water. This
promotes efficient operation of the transducer, with ultrasonic
energy reflected at the exterior surface of support tube
reinforcing ultrasonic energy propagating within the transducer, so
as to provide ultrasonic energy directed outwardly from external
surface of the transducer. In some embodiments, the heart access
devices and systems may further include an introducer. The
introducer may be configured to puncture the tissue to create a
channel. The introducer may be configured to be inserted into a
sheath according to embodiments described herein.
According to some embodiments, a heart access device may include a
sheath and an introducer that includes an energy-transducing
component. FIGS. 12-14 show an example of a heart access device
according to these embodiments.
The introducer 1200 may include a first end 1210 and an opposing,
second end 1220 (also referred to as proximal and distal ends,
respectively), as shown in FIG. 12. In some embodiments, the
introducer 1200 may have the same or different diameters along the
length (between the first end 1210 and the second end 1220). The
diameter of the introducer may be decrease or taper from the first
end 1210 to the second end 1220. In some embodiments, the
introducer may include one section that has the substantially the
same diameter and another section that has a diameter that
tapers.
In some embodiments, the introducer 1200 may include a guide member
1212 extending from or disposed at the proximal or first end 1210.
The guide member 1212 may include an entrance to the interior bore
or channel 1230. The guide member 1212 may have a larger diameter
than the diameter of inner channel or bore of the sheath configured
to receive the introducer 1200. The guide member 1212 may prevent
the introducer from moving further within a sheath. The guide
member 1212 may also be configured to form a tight seal with the
sheath so as to prevent blood leakage.
In some embodiments, the introducer 1200 may include an inner bore
or channel 1230 configured to receive or accept instruments. The
channel 1230 may be configured to receive a guidewire, such as
guidewire 44 or guidewire 1410. The guidewire may be a piggytail
guidewire like guidewire 1410 shown in FIG. 14. The channel 1230
may also be configured to receive or accept an energy source.
In some embodiments, the channel 1230 may be along the entire
length of the introducer. In other embodiments, the channel 1230
may be along a portion of the entire length of the introducer. In
some embodiments, the channel 1230 may begin or have an entrance at
the first end 1210. The guide member 1212 may also include an inner
channel or bore that corresponds to channel 1230. The diameter of
the channel 1230 may correspond to the diameter(s) of the
introducer 1200. For example, the diameter of the channel 1230 may
taper from a point between the first end 1210 and the second end
1220 towards the second end 1220.
The introducer 1200 may include a puncture tip 1222. The puncture
tip 1222 may be configured to puncture tissue, such as the
myocardium, to create an access channel within the tissue. The
puncture tip 1222 may be solid. In other embodiments, the puncture
tip 1222 may be hollow.
In some embodiments, the introducer 1200 may further include at
least one energy-transducing component or element 1240. The
energy-transducing component 1240 may correspond to any of the
components described herein. The introducer 1200 may include one or
more than one energy-transducing component 1240. In some
embodiments, the introducer 1200 may include at least two, three or
four transducing components.
In some embodiments, the energy-transducing component(s) may be
integrated with the introducer 1200. In other embodiments, the
energy-transducing component may be positioned on a sleeve. The
sleeve may be configured to be fixedly disposed around an
introducer as shown in FIG. 12.
The energy-transducing components may be provided in at least one
region or section of the introducer or sheath that is configured to
contact the tissue such as the myocardium. The energy-transducing
region 1240 may be located near the distal end 1220 of the
introducer, as shown in FIG. 12.
In some embodiments, the introducer 1200 may further include at
least one marking configured to assist with the placement of the
introducer. In some embodiments, the guide member 1212 may include
a marking 1214. In other embodiments, the introducer may
additionally or alternatively include markings 1214 along all or
part of the length. In some embodiments, the markings 1214 may be
positioned along the length so that they may be counted to ensure
proper adjustment of the introducer 1200 relative to a sheath
and/or the target site.
In some embodiments, the heart access device may further include a
sheath 1300, as shown in FIG. 13. The sheath 1300 may be configured
to accept or receive an introducer. The sheath 1300 may be similar
to sheath 40. The sheath 1300 may be an elongated tube.
In some embodiments, the sheath 1300 may include an inner bore or
channel 1330 along the length configured to receive or accept
instruments. The channel 1330 may be configured to receive an
introducer. The introducer may be the same or different from the
introducers described herein.
The sheath 1300 may include a first end 1310 and an opposing,
second end 1320 (also referred to as proximal and distal ends,
respectively), as shown in FIG. 13. In some embodiments, the sheath
1300 may have the same or different diameters along the length
(between the first end 1310 and the second end 1320).
In some embodiments, the sheath 1300 may include a guide member
1312 extending from or disposed at the proximal or first end 1310.
The guide member 1312 may include an entrance to the interior bore
or channel 1330. The guide member 1312 may have a portion that has
larger diameter than the diameter of the length of the sheath. The
guide member 1312 may prevent an introducer from moving further
within the sheath.
In some embodiments, the sheath 1300 may include an inner bore or
channel 1330 configured to receive or accept instruments. The
channel 1330 may be configured to an introducer. The channel 1330
may be along the entire length of the sheath. The introducer 1200
may include a section that has a cross section that is equal or
slightly less than a diameter of the channel 1330 of the sheath so
that the channel may the introducer 1200 (but for the guide
member).
In some embodiments, the length of the sheath 1300 may have a
length that is shorter than or substantially equal to the length of
the introducer 1200. As shown in FIG. 14, the introducer 1200 is
longer than the sheath 1300.
The sheath 1300 may include at least one valve to prevent the
leakage of the blood. In some embodiments, the sheath 1300 may
include a valve 1350 on the guide member 1312. The valve 1340 may
be a suction valve.
In some embodiments, the sheath 1300 may include more than one
section. In some embodiments, the sheath 1300 may include an
energy-dispersing or focusing section 1340. The energy-focusing
section 1340 may be configured to contact or touch an outside
surface of the introducer that includes the energy-transducing
components.
The energy focusing section 1340 may include one or more than
energy-dispersing or focusing elements 1342 (also referred to as
components). The energy-dispersing or focusing elements 1342 may be
configured to focus the energy from the energy-transducing
components to a specific area of the tissue. The position and or
pattern of the energy-dispersing or focusing elements 1342 may be
based on the desired point(s) or location(s) of the tissue at which
energy should be applied. The pattern of the energy-focusing
elements may correspond to the pattern of the energy-transducing
components provided on an introducer (in an associated manner). As
shown in FIG. 13, the pattern of the energy-focusing elements 1342
may correspond to the pattern of energy-transducing components
1240.
The energy-focusing elements 1342 may depend on the
energy-transducing components to be used. For example, if the
energy-transducing components are ultrasound, the sheath does not
need energy focusing elements 1342 to transmit or disperse the
energy to the tissue. On the other hand, if the energy-transducing
components are heat, the sheath may include energy focusing
elements 1342 to transmit or disperse the energy to the tissue.
In some embodiments, the thickness of the sheath may vary. In some
embodiments, the energy focusing section 1340 may be thinner than
the other sections of the sheath.
FIG. 14 shows an example of an assembly of a heart access device
1400 having the introducer 1200 and the sheath 1300. As shown in
FIG. 14, the diameter of the proximal or first ends of the
introducer 1200 and the sheath 1300 may correspond to each other to
prevent leakage of blood. In some embodiments, the diameter of the
guide members 1212 and 1312 that may correspond to each other to
prevent leakage of blood. The guide member 1212 of the introducer
may a cross section that is larger than an inner diameter of the
guide member 1312.
In some embodiments, the access devices and the systems may further
include a sealing device configured to close the hole or channel
made by the procedure. In some embodiments, upon completion of the
desired procedure, the access port may be closed as described
herein and all or parts the heart access device may be withdrawn.
The sealing device may include an elongated section. The sealing
device may be a plug.
In some embodiments, the sealing device may be configured to be a
port for further procedures. In some embodiments, the port may be
further configured to be attached to a sealing device delivery
device, such as a sealing device introducer. In some embodiments,
the sealing device may include a radiopaque marker. The radiopaque
marker may be configured to show the sealing on a medical imaging
device for later procedures. The medical imaging device may include
but is not limited to X-ray, MM and CT. In some embodiments, the
radiopaque marker may be a balloon provided at one of the sealing
device. The balloon may be capable of being expanded after
implantation of the plug.
In some embodiments, the sealing device may further include at
least one sensor configured to monitor the heart. For example, the
cardiac conduction currents in the myocardium may be monitored.
In some embodiments, the sealing device may be one material. In
other embodiments, the plug may be constructed or made of different
materials. The sealing device may be constructed or made of a
biocompatible material that expands upon insertion. The sealing
device may be constructed or made of a dehydrated biocompatible
material that expands upon hydration or exposure to biological
fluids. The sealing device may be constructed or made of a polymer
or material that has shape memory characteristics.
In some embodiments, the sealing device may include a base. The
base may be configured to be removably attached to a delivery
device, such as a sealing device introducer. The base may include
an opening along all or part of the height (perpendicular to the
diameter) to communicate with a delivery device. The base may be
constructed or made of a biocompatible material, such as
Teflon.
FIGS. 16(A)-(D) show examples of different sealing devices. FIG.
16(A) shows an example of a sealing device 1610 composed of a wound
bioabsorbable material 1612. The bioabsorable material may have a
hollow interior or center so as to promote the formation of scar
tissue by allowing more absorption of the tissue and blood. The
sealing device 1610 may include a base 1614 having an opening
1616.
FIG. 16(B) shows an example of a sealing device 1620 of a
pre-formed hydrophilic material 1622. The hydrophilic material 1622
may be of any shape. The sealing device 1620 may include a base
1624 having an opening 1626.
FIG. 16(C) shows another example of a sealing device 1630 of a
bioabsorbable material 1632. The material may be wound as shown in,
for example, FIG. 16(a). The sealing device 1630 may further
include one or more than one extending member 1638 configured to
contact a surface of the tissue so as to promote the flow of
biological fluid and formation of tissue. The extending members
1638 may be flexible. The sealing device 1630 may include a base
1634 having an opening 1636.
FIG. 16(D) shows another example of a sealing device 1640 of
multiple materials. The sealing device 1640 may include an
elongated section 1642 constructed or made of a pre-formed
hydrophilic material. The sealing device 1640 may further include a
clip section 1648 constructed or made of a memory shape alloy, such
as Nitinol. The clip section 1648 may include more than one
extending member configured to open upon an application of radial
force. The clip section 1648 may be configured to anchor the
sealing device within the access channel. The sealing device 1630
may include a base 1644 having an opening 1646.
In some embodiments, the sheath may further include a mechanism to
promote linear movement of the sheath with respect to a device
within its interior bore or channel. In some embodiments, a sheath
may include internal threads 1360, as shown in FIG. 17. The
internal threads 1360 may be disposed adjacent to the proximal or
first end 1310. The internal threads 1360 may be configured or
structured to cause the sheath to move distally when a
corresponding device engages the internal threads. In some
embodiments, the internal threads may be female threads. The
mechanism may also be configured to gauge the location of the
corresponding device with respect to the sheath and the access
channel.
The corresponding device may be an introducer. In some embodiments,
the introducer may be configured to deliver energy like the
introducer shown in FIG. 12. In other embodiments, the introducer
may be configured to deliver and anchor a sealing device in the
access channel in the tissue.
FIG. 18 shows a sealing device introducer 1800 according to
embodiments. In some embodiments, the introducer 1800 may include a
first end 1810 and an opposing, second end 1820 (also referred to
as proximal and distal ends, respectively), as shown in FIG. 12. In
some embodiments, the introducer 1800 may have the same or
different diameters along the length (between the first end 1810
and the second end 1820).
In some embodiments, the proximal or first end 1810 may include a
guide member 1812. The guide member 1812 may include an entrance to
the interior bore or channel 1830. The guide member 1812 may have a
larger diameter than the diameter of interior channel or bore the
sheath configured to receive the introducer 1800. The guide member
1812 may prevent the introducer from moving further within a
sheath. The guide member 1812 may also be configured to form a
tight seal with the sheath so as to prevent blood leakage.
In some embodiments, the introducer 1800 may include an inner bore
or channel 1830. In some embodiments, the channel 1830 may be along
the entire length of the introducer. In other embodiments, the
channel 1830 may be along a portion of the entire length of the
introducer. In some embodiments, the channel 1830 may begin or have
an entrance at the first end 1810. The guide member 1812 may also
include an inner channel or bore that corresponds to the channel
1830.
In some embodiments, the introducer 1800 may include a release
mechanism configured to release a sealing device 1840 disposed at
the distal or second end 1820. The introducer 1800 may include a
spring mechanism that is disposed within the channel 1830. The
guide member 1812 may be configured to activate the release
mechanism, for example, by being depressed.
The second end 1820 may include a holding member 1822 configured to
releasably hold a sealing device 1840. The holding member 1822 may
be configured to releasably hold and mate a base of the sealing
device. In some embodiments, the holding member 1822 may be a
protruding member that corresponds to the opening provided in the
base as shown in FIGS. 16(A)-16(D).
The sealing device 1840 is not limited to the sealing device shown
and may be any sealing device including those described herein. The
sealing device 1840 may include an elongated section 1842
constructed or made of a pre-formed hydrophilic material and a clip
section 1844 constructed or made of a memory shape alloy, such as
Nitinol. The clip section 1844 may include more than one extending
member configured to open upon an application of radial force
(i.e., being released). The clip section 1844 may be configured to
anchor the sealing device within the access channel.
In some embodiments, the sealing device introducer may further
include a mechanism to promote linear movement of the sheath with
respect to the introducer. The mechanism may also be configured or
structured to gauge the location of the introducer with respect to
the sheath and the access channel.
In some embodiments, the introducer may include external threads
1860. The internal threads 1860 may be disposed adjacent to the
proximally end 1810. The threads 1860 may be configured to cause
the sheath to move away from the access channel (proximally) when
the threads 1860 engage the internal threads 1360 of the sheath
1300. The threads 1860 may be complimentary to the threads 1360 of
the sheath 1300. In some embodiments, the threads 1860 may be male
threads. This mechanism may be configured to allow removal of the
sheath and introducer after the plug is released and anchored into
the channel.
In some embodiments, the access devices and the systems may be
configured to deliver a tissue-stabilizing composition before or
after the access device is properly positioned. The introducer may
be configured to receive a tissue-stabilizing composition delivery
device configured to deliver a tissue-stabilizing composition into,
around, or adjacent to the tissue. The tissue-stabilizing
composition may be a heat shapeable biomaterial formulated for in
vivo administration in an area surrounding an access port or
channel. The tissue-stabilizing composition is not limited to those
described herein.
In some embodiments, the access devices and the systems may include
a tissue-stabilizing composition delivery device. In some
embodiments, the tissue-stabilizing composition delivery device may
be a needle. The needle may have one or more than one opening
configured to deliver the tissue-stabilizing composition. In
further embodiments, the sheath may include a plurality of ports on
the surface near the distal end to deliver the tissue-stabilizing
composition into, around or adjacent to the surrounding tissue.
In some embodiments, all or at least one part of the heart access
device may be configured to remain in the heart. In some
embodiments, all or at least one part of the heart access device
may be bioabsorbable. In other embodiments, all or parts of the
heart access device may be configured to be removed from the
heart.
In some embodiments, the access device may further include one or
more sensors. The sensors may be provided on a surface of the
access device. In some embodiments, the sheath may include at least
one temperature sensors configured to measure the tissue
temperature. The temperature sensor(s) may be provided on the
surface of the sheath on the end configured to be inserted into the
tissue to be heated.
Energy Transduction
In some embodiments, the systems, devices, and methods may provide
energy-transducing elements configured or structured to apply
energy to surrounding tissue and/or a heat shapeable biomaterial.
In certain embodiments, the energy delivered may be below a
temperature sufficient for effecting crosslinking of the
biomaterial and surrounding tissue. In some embodiments, the energy
may be delivered to the tissue needed for treatment at or adjacent
a tissue structure. The energy may heat surrounding tissue and/or
shapeable biomaterial or cause the temperature of the surrounding
tissue and/or shapeable biomaterial to rise. Examples of energy
sources and energy-transducing elements configured or structured
for energy transduction are described herein.
In other embodiments, the energy being delivered reduces the
temperature of the surrounding tissue. In these embodiments, the
sheath is inserted into the tissue and a cryo-probe, capable of
reducing the temperature of the tissue is provided.
Moderate heat is known to tighten and shrink the collagen tissue as
illustrated in U.S. Pat. Nos. 5,456,662 and 5,546,954. It is also
clinically verified that thermal energy is capable of denaturing
the tissue and modulating the collagenous molecules in such a way
that treated tissue becomes more resilient ("The Next Wave in
Minimally Invasive Surgery" MD & DI pp. 36-44, August 1998).
The general method according to embodiments applies appropriate
heat to the tissues, and causes them to shrink and tighten. It may
be performed in a minimal invasive fashion, which is often less
traumatic than surgical procedures and may be the only alternative
method, wherein other procedures are unsafe or ineffective.
Ablative treatment devices have an advantage because of the use of
a therapeutic energy that is rapidly dissipated and reduced to a
non-destructive level by conduction and convection, to other
natural processes.
Radiofrequency (RF) therapeutic protocol has been proven to be
highly effective when used by electrophysiologists for the
treatment of tachycardia, atrial flutter and atrial fibrillation;
by neurosurgeons for the treatment of Parkinson's disease; by
otolaryngologist for clearing airway obstruction and by
neurosurgeons and anesthetists for other RF procedures such as
Gasserian ganglionectomy for trigeminal neuralgia and percutaneous
cervical cordotomy for intractable pains. Radiofrequency treatment,
which exposes a patient to minimal side effects and risks, is
generally performed after first locating the tissue sites for
treatment. Radiofrequency energy, when coupled with a temperature
control mechanism, can be supplied precisely to the
device-to-tissue contact site to obtain the desired temperature for
treating a tissue or for effecting the desired shrinking of the
host collagen or injected biomaterial adapted to immobilize the
biomaterial in place.
Edwards et al. in U.S. Pat. No. 6,258,087 describes an expandable
electrode assembly comprising a support basket formed from an array
of spines for forming lesions to treat dysfunction in sphincters.
Electrodes carried by the spines are intended to penetrate the
tissue region upon expansion of the basket. Similarly, Tu in U.S.
Pat. No. 6,267,781 teaches an ablation device for treating valvular
annulus or valvular organ structure of a patient, comprising a
flexible elongate tubular shaft having a deployable spiral wire
electrode at its distal end adapted to contact/penetrate the tissue
to be treated and to apply high frequency energy to the tissue for
therapeutic purposes. Tu et al. in U.S. Pat. No. 6,283,962
discloses a medical ablation device system for treating valvular
annulus wherein an elongate tubular element comprises an electrode
disposed at its distal section that is extendible from an opening
at one side of the tubular element, the energy generator, and means
for generating rotational sweeping force at the distal section of
the tubular element to effect the heat treatment and the rotational
sweeping massage therapy for target tissues. U.S. Pat. No.
5,980,563 describes certain ablation methods and apparatus for
treating atherosclerosis. Similarly, U.S. Pat. No. 6,882,885 to
Solarant describes certain heating methods for tissue contraction.
U.S. Pat. Nos. 6,485,489 and 6,306,133 describe certain ablation
catheter systems for applying heat to an annulus defect to shrink
or tighten the tissue.
Ultrasound is cyclic sound pressure with a frequency greater than
the upper limit of human hearing. Although this limit varies from
person to person, it is approximately 20 kilohertz (20,000 hertz)
in healthy, young adults and thus, 20 kHz serves as a useful lower
limit in describing ultrasound. The production of ultrasound is
used in many different fields, typically to penetrate a medium and
measure the reflection signature or supply focused energy. The
reflection signature can reveal details about the inner structure
of the medium, a property also used by animals such as bats for
hunting. The most well-known application of ultrasound is its use
in sonography to produce pictures of fetuses in the human womb.
There are a vast number of other applications as well. Ultrasound
energy has two potential physiological effects: it enhances
inflammatory response and it can heat soft tissue. Ultrasound
energy produces a mechanical pressure wave through soft tissue.
This pressure wave may cause microscopic bubbles in living tissues
and distortion of the cell membrane, influencing ion fluxes and
intracellular activity. When ultrasound enters the body, it causes
molecular friction and heats the tissues slightly. This effect is
typically very minor as normal tissue perfusion dissipates most of
the heat, but with high intensity, it can also cause small pockets
of gas in body fluids or tissues to expand and contract/collapse in
a phenomenon called cavitation. Ultrasound has been used
successfully to shrink the mitral valve annulus (see ReCor Medical
press release, 2010).
Another mechanism that may be used to heat tissue in a localized
for to increase stability is microwave radiation. Typically,
thermal coagulation of tissue involves the use of microwaves to
induce an ultra-high-speed (2450 MHz) alternating electric field,
causing the rotation of water molecules. Although the use of
microwaves for tissue ablation is not new, the majority of the
clinical experience with this technique to ablate liver tumors
comes from Japan. Percutaneous microwave ablation was first used as
an adjunct to liver biopsy in 1986, but it has since been used for
hepatic tumor ablation. As with RF ablation, microwave ablation
involves placement of a needle electrode directly into the target
tissue.
Tissue-Stabilizing Compositions
Moderate heat is known to tighten and shrink the collagen tissue.
The same shrinking/tightening techniques may also be applicable to
stabilize injected biomaterial that allow stabilization of the
tissue surrounding the apical access device wherein the injectable
biomaterial is suitable for penetration and heat-initiated
shrinking/tightening. The general method applies appropriate heat
to the tissues, and causes them to shrink and tighten. It may be
performed in a minimal invasive fashion, which is often less
traumatic than surgical procedures and may be the only alternative
method, wherein other procedures are unsafe or ineffective.
Ablative treatment devices may have an advantage because of the use
of a therapeutic energy that is rapidly dissipated and reduced to a
non-destructive level by conduction and convection, to other
natural processes.
A variety of materials may be injected to improve the stability of
the tissue or improve the sensitivity of the tissue to the heat
treatment. In some embodiments, the composition that is
administered is a gelatin-resorcinol-formaldehyde (GRF) glue (see
Nguyen, et al. (1999) Eur J Cardiothorac Surg 15:496-500). In other
embodiments, the material is a
gelatin-resorcinol-formaldehyde-glutaraldehyde (GRFG) glue (see
Nomori and Horio (1997) Ann Thorac Surg 1997 63:352-355). In
another embodiment, the composition or compound is a
gluteraldehyde/bovine serum albumin solution. The material may be a
BioGlue Surgical Adhesive consisting of two components, a 10%
glutaraldehyde solution and a 45% bovine serum albumin solution,
which are kept separate until the time of application (see
BioGlue.RTM. Product Information. CryoLife, Inc, Kennesaw, G A,
1998).
In some embodiments, the material may be a biomolecular material
comprising at least one biomolecule which has been mixed at high
concentration with an aqueous solvent. The biomolecule(s) may be
typically proteinaceous but it is envisaged that other naturally
occurring biomolecules could be used as alternatives. Further,
analogues of biological, biodegradable polypeptides may also be
used. Analogues of biological, biodegradable polypeptides useful in
the solders of the disclosure include synthetic polypeptides and
other molecules capable of forming the material but which do not
cause adverse reaction in the tissue undergoing repair. Examples of
suitable proteins include albumins, collagen, fibrinogen and
elastin. Suitable proteins are typically those which can be
cross-linked to form a matrix and which can be resorbed by the
body. Where combinations of proteins are used it is envisaged that
those combinations will be of proteins having similar denaturation
temperatures. An example is the combination of albumin and
collagen. Use of different albumins is contemplated including
bovine, horse, human, rat, ovine and rabbit albumin. The choice of
a particular albumin may be made to reduce immunological reaction
in the patient to the material. It is envisaged that there will be
circumstances where the albumin used may be chosen to match the
patient's blood type and possibly even more specifically with
regard to histocompatibility markers of the patient in question.
The solvent may be typically water but other aqueous solvents
including saline may be used provided that any salt etc. present
does not adversely affect the material upon denaturation. Various
adjuvants may be added to the material to promote rapid or more
complete tissue healing, e.g. fibrinogen (for blood vessels),
growth factors, sodium hyaluronate (for improved viscous handling
and possibly better healing), hormones, and/or anticoagulants, such
as heparin. Various fibrous materials may be added to the material
to improve the strength (e.g. collagen or polytetrafluoroethylene
fiber (which is sold under the brand names goretex and teflon) or
ceramic fibers). The fibers may typically be biocompatible
polymers.
There are a variety of collagen-based compositions available that
may be used in the present disclosure. These may include type I and
type III injectable human collagen product derived from human
sources (containing type I and type III collagen in a proportion of
44:56) (see e.g. Liu, et al. (2005) Semin Plast Surg. 19: 241-250).
Similarly, Bovine injectable collagen (Zyderm I.RTM., Zyderm
II.RTM., and Zyplast.RTM. collagen implants; Inamed Corporation,
Santa Barbara, Calif.) are readily available. U.S. Pat. No.
4,837,285 describes certain collagen-based compositions for
augmenting soft tissue, wound dressings, implants, injectable
formulations or other drug delivery systems, comprising resorbable
collagen matrix beads. U.S. Pat. No. 6,110,212 describes the use of
certain elastin-based biomaterials for tissue repair or
replacement.
Fibrinogen compositions are also readily available. These may
include RiaSTAP.TM., a heat-treated, lyophilized fibrinogen
(coagulation factor I) powder made from pooled human plasma. This
composition may include fibrinogen, human albumin, L-arginine
hydrochloride, sodium chloride and sodium citrate. In addition,
Oss-Ronen and Seliktat described certain polymer-conjugated albumin
and fibrinogen composite hydrogels in which serum albumin was
conjugated to poly-(ethylene glycol) (PEG) and cross-linked to form
mono-PEGylated albumin hydrogels.
Albumin compositions have also been used for tissue repair. In some
instances, the albumin is stabilized with additional compounds or
compositions, such as genepin to increase crosslinking. In
addition, chitosan has been used to improve the malleability of
albumin compositions, as well as to bind to collagen. Chitosan has
also been modified with lactobionic acid and p-azidebenzoic acid,
which can be cross-linked with UV light. U.S. Pat. No. 5,292,362
describes certain tissue bonding materials including albumins and
fibrinogens.
Biomaterials based upon elastin and elastin-derived molecules are
increasingly investigated for their application in tissue
engineering. This interest is fuelled by the remarkable properties
of this structural protein, such as elasticity, self-assembly,
long-term stability, and biological activity. Elastin can be
applied in biomaterials in various forms, including insoluble
elastin fibres, hydrolysed soluble elastin, recombinant
tropoelastin (fragments), repeats of synthetic peptide sequences
and as block copolymers of elastin, possibly in combination with
other (bio) polymers. In this review, the properties of various
elastin-based materials will be discussed, and their current and
future applications evaluated. In certain embodiments, tropoelastin
monomers and lysyl oxidase can be prepared and suspended an aqueous
solution (e.g., water or saline) or in a lyophilized form and kept
separate from each other until right before use. U.S. Pat. No.
6,110,212 describes certain elastin-based materials that can be
useful for stents. These materials may also be useful in the
present disclosure.
Other compositions known in the art that allow strengthening of the
tissue can also be used.
Detailed Methods of Providing Stable Access to a Heart Chamber
& Delivering a Prosthesis
In some embodiments of the present disclosure, methods for
providing a stable access to a heart chamber for medical procedures
are provided. In further embodiments, methods for delivering a
prosthesis to a target site in or near a heart are provided.
In some embodiments of the present disclosure, a method of
providing access to a target site in or near a heart is provided.
The method includes (i) providing an access channel into the
chamber; (ii) providing an energy-transducing element configured to
provide heat to tissue surrounding the access channel; and (iii)
applying energy to the tissue.
In some embodiments, the methods may include providing an access
channel into the chamber. In certain embodiments, the steps of
providing an access channel may include introducing a heart access
device according to embodiments into a heart chamber. In some
embodiments, the heart access device may be introduced by any known
method. In some embodiments, the step of introducing a heart access
device described herein may include the steps of the method shown
and described with respect to FIGS. 2(A)-(D).
In some embodiments, the access channel may be disposed at or near
the apex of the heart. In other embodiments, the access channel may
at other areas of the heart.
In some embodiments, the steps of introducing the heart access
device 400 may include inserting the sheath 40 into the apex of the
heart and positioning the sleeve 45 inside the heart tissue (see
FIG. 5).
In certain embodiments, in particular in patients in need of
additional stabilization of heart tissue such as the elderly (above
65), the method may optionally include a step of administering or
delivering a tissue-stabilizing composition. The tissue-stabilizing
composition may be administered by threading a needle 60 or other
device sufficient to administer a tissue-stabilizing composition
through (FIG. 6) or alongside (FIG. 7) the sheath. In some
embodiments, a tissue-stabilizing composition may be administered
into the tissue surrounding the sheath as shown in FIG. 6. In other
embodiments, a tissue-stabilizing composition may be administered
to the tissue surrounding the access port as shown in FIG. 7. In
some embodiments, the tissue-stabilizing composition may be a heat
shapeable biomaterial formulated for in vivo administration in an
area surrounding an access port. The heat shapeable biomaterial may
be formulated for in vivo administration in an area surrounding an
access port.
In some embodiments, the methods may further include the steps of
providing an energy source 70 and applying energy. In some
embodiments, the energy source may be configured to provide heat to
tissue surrounding the access channel and energy may be applied to
the tissue. Energy may be delivered to the tissue at a level
sufficient to increase the structural stability of the tissue. In
some embodiments, the energy source 70 may be provided by an
introducer.
In other embodiments, the energy source may be configured to
additionally or alternatively heat an injected tissue-stabilizing
composition. The tissue-stabilizing composition may have been
injected into, around, or adjacent to the tissue. In some
embodiments, the methods may include applying heat sufficient to
shape the biomaterial and immobilize the biomaterial at about the
access port after injection. In certain embodiments, the heat
delivered may be below a temperature sufficient for effecting
crosslinking of the biomaterial and surrounding tissue.
The methods may further include a step to anchor the access device
so that cardiac procedures may be performed. In some embodiments, a
balloon may be used to position the access system. In other
embodiments, another positioning tool may be used. In some
embodiments, the fasteners may be used to anchor the access device.
The fasteners may include but are not limited to anchors, stent
expansion, screws or biological glues. As shown in FIG. 8, after
stabilization of the tissue, an expandable balloon may be advanced
over the guide wire into the cardiac chamber, illustratively in the
form of balloon 80. The balloon 80 may be advanced through the
sheath and expanded into the ventricular space.
When inflated, as depicted in FIG. 8, the balloon may generally be
in the form of a surface of revolution about a central axis
coincident with proximal-to-distal axis of the catheter. The
diameter of the balloon may typically be about 20 mm and may
usually be formed from a polymer such as nylon with a wall
thickness of about 8 microns to about 30 microns.
The balloon may then pulled outwards to move the sleeve into a
position in which the distal end 41 of the sleeve 45 is in line or
coincident with the interior of the tissue 82. The balloon may then
deflated and withdrawn. When deflated, the balloon may collapse
inwardly to form a relatively small diameter structure. The balloon
may be fabricated by blow-molding using techniques that are known
in the art. This positioning of the sheath may be accomplished
either before or after the tissue strengthening procedure.
The sleeve 45 may then be anchored into the tissue using any
biocompatible fasteners. The fasteners may include but are not
limited to anchors, stent expansion, screws or biological
glues.
After the access system has been stabilized, an interventional
procedure may then be performed by insertion of instruments through
the sheath. In some embodiments, this may include implanting or
delivering a prosthesis. The prosthesis may be any known cardiac
prosthesis. The prosthesis may include but are not limited to
replacement or repair valve devices. In some embodiments, after a
stable access is provided, the methods may further include steps to
deliver a prosthesis to a target site in or near a heart. The
methods may further iv) introducing a delivery system into the
heart through an access channel, wherein a prosthesis is disposed
on the delivery member attached to the delivery system; (v)
advancing the prosthesis to the target site; and (vi) disengaging
the prosthesis from the delivery member at the target site for
implantation.
After completion of the procedure, the sealing device 90 may be
inserted into the sheath. The sealing device may be a plug. The
plug may be typically made of a material that expands upon
insertion, for example, a dehydrated material that expands upon
hydration. The surface of the plug facing the cardiac chamber may
be typically made of a polymer material that encourages rapid
endothelialization. Normally, endothelial cells (EC) migrate and
proliferate to cover denuded areas until confluence is achieved.
Although the process of recognition and signaling to determine
specific attachment receptor response to attachment sites is
incompletely understood, regular availability of attachment sites,
more likely than not, would favorably influence attachment and
migration. There have been numerous attempts to increase
endothelialization of devices such as implanted stents, including
covering with a polymeric material (see e.g. U.S. Pat. No.
5,897,911), imparting a diamond-like carbon coating (see e.g. U.S.
Pat. No. 5,725,573), covalently binding hydrophobic moieties to a
heparin molecule (see e.g. U.S. Pat. No. 5,955,588), coating with a
layer of blue to black zirconium oxide or zirconium nitride (see
e.g. U.S. Pat. No. 5,649,951), coating with a layer of turbostratic
carbon (see e.g. U.S. Pat. No. 5,387,247), coating with a thin
layer of a Group VB metal (see e.g. U.S. Pat. No. 5,607,463),
imparting a porous coating of titanium or of a titanium alloy, such
as Ti--Nb--Zr alloy (see e.g. U.S. Pat. No. 5,690,670), coating
with a synthetic or biological, active or inactive agent, such as
heparin, endothelium derived growth factor, vascular growth
factors, silicone, polyurethane, or polytetrafluoroethylene, (see
e.g. U.S. Pat. No. 5,891,507), coating with a silane compound with
vinyl functionality, then forming a graft polymer by polymerization
with the vinyl groups of the silane compound (see e.g. U.S. Pat.
No. 5,782,908), grafting monomers, oligomers or polymers onto a
surface using infrared radiation, microwave radiation or high
voltage polymerization to impart the property of the monomer,
oligomer or polymer (see e.g. U.S. Pat. No. 5,932,299). Any such
materials, or others known in the art, may be used to manufacture
all or part of the plug to be used in the present disclosure.
After insertion of the plug 90, the sleeve 45 may be removed from
the remainder of the sheath 400 and the remainder of the sheath 400
may be withdrawn from the body (see FIG. 9). As shown in FIGS. 10
and 11, typically, the sleeve may be attached by a snap mechanism
1010 to the remainder of the sheath or may be attached via a
screwtop mechanism 1110 to the remainder of the sheath. Other
mechanisms that may be used to separate the sleeve from the
remainder of the sheath are also envisioned herein.
In another embodiment of the disclosure, the sleeve may be removed
completely, leaving the sealing device (the plug) in place. In some
embodiments, the sealing device (the plug) may be fabricated from a
biodegradable material, which may decrease the tendency for
infection that is associated with any foreign body left in
place.
According to some embodiments, the steps for creating or accessing
an access channel may depend on the access device used and type of
procedure performed. An example of a minimally invasive method of
providing apical access to heart chamber for a medical procedure is
shown in FIGS. 19 through 27. The method shown may also be
performed percutaneously. FIGS. 28 through 39 show an example of
the method being performed on a pig heart.
According to some embodiments, the step of creating the access
channel may include identifying the location of apex with medical
imaging, such as fluoroscopy or echocardiography. The location of
the left-ventricle (LV) apex may be identified. In FIG. 19, the LV
apical region 1910 may be located and an incision 1920 may be
made.
The step of creating the access channel may further include
introducing an access device into the LV region. The access device
may include an introducer and a sheath. Example of an access
devices are shown in FIGS. 20 and 28. In FIG. 20, the access device
2000 includes an introducer 2010 and a sheath 2020. The introducer
2010 may include energy-transducing components 2012 located close
to the distal end 2014. The introducer 2010 may be connected to a
power source 2040. The energy source and the energy-transducing
components may be according any of the embodiments described
herein. In FIG. 28, the access device 2800 includes a sheath 2810
and an introducer 2820.
The step of introducing an access device to the heart may include
positioning and inserting the introducer into the heart. The
introducer 2820 may be first positioned in the LV region 2900, as
shown in FIG. 28. Next, the introducer 2820 may be inserted and
advanced into the LV region 2900, as shown in FIG. 29. The
introducer may be guided by a guidewire. The 2820 may be configured
to puncture the tissue of the heart, the myocardium, so as to
create an access channel in the myocardium. As shown in FIG. 20,
the introducer 2010 may be guided by guidewire 2030 into the
myocardium.
The introducer may be advanced so that the energy-transducing
components may be adjacent to or substantially adjacent to the
myocardium of the LV region and the distal end 2014 may be located
inside a heart chamber. After the introducer is properly positioned
in the LV region 1910, the sheath may then be advanced. As shown in
FIGS. 20 and 21, the sheath 2020 may be advanced over the
introducer 2010 until the distal end 2024 of the sheath 2020 is
located within the chamber. In some embodiments, the sheath 2020
may be advanced until the energy dispersing region corresponds to
the region of the introducer including the energy-transducing
components. FIG. 31 also shows the sheath 2810 being be moved or
forwarded along the introducer into the LV region 2900.
After the sheath and the introducer are properly positioned within
the myocardium as shown in for example, FIGS. 22 and 32, the energy
may be applied. As shown in FIG. 22, energy 2210 may be dispersed
from the energy-transducing components 2012 through the sheath 2020
to the tissue surrounding the access device 2000. The
energy-transducing components 2012 may be provided power by a power
source 2040. FIG. 33 also shows energy being applied to tissue
surrounding the sheath 2810.
The surrounding tissue 2310 treated by energy strengthens and
radially contracts onto the sheath, as shown in FIG. 23. FIG. 34
shows treated tissue. The treated tissue has a change of color
around insertion point. After the tissue has been treated, the
sheath may remain in place for medical procedure(s). Interventional
or diagnostic procedures may be performed through the sheath. The
valve 2022 may be closed to restrict blood loss. After the
procedures have been performed, a sealing device may be introduced
into the access channel.
In some embodiments, as shown in FIGS. 24 through 26, a sealing
device 2420 may be introduced by a sealing device introducer 2410.
The sealing device introducer 2410 may be according to the
embodiments described herein. The sealing device introducer 2410
may be inserted into the sheath to position sealing device 2420.
The sealing device 2420 may be pushed along and within the sheath
by rotating the sealing device introducer 2410, as shown in FIGS.
24 and 25. In some embodiments, the sealing device introducer 2410
may include threads 2412 at the proximal end that are configured to
engage corresponding threads 2024 of the sheath 2020. A user may
know that the sealing device is properly positioned within the
access channel by counting the rotations of the sealing device
introducer.
After the sealing device is positioned within the access channel in
the myocardium, the sheath may be removed from the access channel.
The sheath 2020 may be retracted back with the sealing device
introducer 2410 towards the user, as shown in FIG. 26. The sealing
device may remain in the myocardium. FIG. 27 shows an example of a
sealing device 2420 anchored into the access channel formed in the
myocardium. FIG. 35 also shows a sealing device anchored into the
access channel.
FIGS. 36 through 39 show the results of the method performed on the
pig shown in FIGS. 28 through 34. FIG. 36 shows no leakage of blood
through the sealing device about 1 hour after the procedure was
completed. FIG. 37 shows an explanted heart and with the sealing
device trimmed showing sufficient closure of the access channel.
FIG. 38 shows the sealing device completely covering the access
channel. FIG. 39 shows a controlled localized tissue treated with
mechanical strengthening by energy application around the insertion
site (the access channel).
Kits
According to some embodiments, one, some or all components of the
system and device may be configured for single use or be
disposable. In some embodiments, one, some or all components may be
sterilized. According to some embodiments, a portion or combination
of the single use items may be sold as kit.
In some embodiments, the kit may include a heart access device
according to embodiments. The kit may include a sheath and at least
one energy-transducing element. In further embodiments, the kit may
further include an introducer. In some embodiments, the kit may
include a sleeve. In some embodiments, the kit may include a
sealing device. In some embodiments, the kit may include a sealing
device introducer.
While various embodiments of the disclosure have been described,
the description is intended to be exemplary rather than limiting
and it will be apparent to those of ordinary skill in the art that
many more embodiments and implementations are possible that are
within the scope of the disclosure.
* * * * *
References